Polyphenylene ether resins have various properties such as excellent mechanical properties, electrical properties, acid and alkali resistance, and heat resistance, low specific gravity and water absorptivity, and good dimensional stability, and are thus widely used as materials in consumer electronics, office automation devices, office equipment, information devices, automobiles, and so forth. In recent years, polyphenylene ether resin compositions have also been considered for application in automobile head lamps and also light reflective molded articles that are used in projectors, various lighting equipment, and the like. Parts that are used in applications such as described above are normally surface treated by aluminum vapor deposition prior to use, and there is demand for surface smoothness of a mirror surface of vapor deposited aluminum to be maintained even upon long-term exposure to high-temperature conditions.
However, it has been found that in a situation in which a metal such as aluminum is vapor deposited on a molded article surface formed from a conventional polyphenylene ether resin, the smoothness of the surface is reduced upon long-term exposure of the surface to high-temperature conditions. The cause of this reduction in surface smoothness is thought to be due to the fact that although the entire surface of a molded article appears to be uniformly covered by a vapor deposited aluminum film, there are locations appearing like extremely fine pin holes where the surface of the molded article is not covered by the vapor deposited aluminum film, and upon long-term exposure of these locations to high temperatures, depressions form at these locations such that eventually a large number of depressions that are large enough to be visibly identifiable are formed in the surface of the molded article.
PTL 1, for example, describes a light reflective part for which the occurrence of white spots after aluminum vapor deposition is suppressed.
Moreover, PTL 2 discloses a technique relating to a resin composition that contains a polyphenylene ether resin and a compound such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. It is disclosed that the technique described in PTL 2 can suppress discoloration due to heat during extrusion processing.